Process symbols diagrams

The expense of fabrication and erection of this equipment certainly warrants recognition of the quality of methods as well as extra checking time prior to initiating fabrication. The general process symbol diagram of Figure 8-1 will be used as reference for the systems and methods pre-... 

Graphical Symbols for Process Flow Diagrams, ASA Y32.ll.1961, American Society of Mechanical Engineers, New York. 

Block flow diagrams are frequently used to represent chemical processes. These diagrams indicate by blocks the key processing steps of chemical reaction and separation. Considerably more detail is shown in process flow diagrams, which also include the auxiliary operations and utilize symbols that depict the type of equipment employed. 

Table 1.1 is a list of the commonly used continuous separation operations based on interphase mass transfer. Symbols for the operations that are suitable for process flow diagrams are included in the table. Entering and exit vapor and liquid and/or solid phases are designated by V, L, and S, respectively. Design procedures have become fairly well standardized for the operations marked by the superscript letter a in Table 1.1. These are now described qualitatively, and they are treated in considerable detail in subsequent chapters of this book. Batchwise versions of these operations are considered only briefly.

Figure 4.6 (a) Three large-scale PFRs and (b) the symbol used commonly to represent a PFR in process flow diagrams. 

ANSI, "Graphical Symbols for Process Flow Diagrams ", ANSI Y32.I I, 2003. 

SAA, "Graphical Symbols For Process Flow Diagrams For The Food Industry ", SAA AS 1109. 

Flow diagram—a simplified diagram that uses process symbols to describe the primary flow... 

One of the more difficult tasks a new process technician is faced with is memorizing the hundreds of symbols and diagrams associated with the process industry. These process symbols form the... 

Some symbols are common between plants, whereas others change depending on the company. In other words, two different symbols may be used to identify a centrifugal pump or a valve, for example. Some standardization of process symbols and diagrams is taking place, but the process technician must learn what symbols his or her employer uses. The symbols shown in this chapter reflect a wide variety of petrochemical and refinery operations. 

Symbols and diagrams have been developed for most pieces of industrial equipment, process flows, and instrumentation. The symbols covered in this chapter include those typically used with valves, piping, tanks, pumps, compressors, steam turbines, motors, heat exchangers, cooling towers, furnaces, boilers, distillation columns, and reactors. These symbols are used in process symbols to describe a process unit. 

Whatever type of compressor is being used, the symbol used in process flow diagrams is as shown in Fignre 9.3. 

Figure 1.4 Symbols for Drawing Process Flow Diagrams...

Process simulation software typically will produce a flowsheet, but this is probably not a true process flow diagram and should not be used as one in a report. There are two reasons for this. First, the simulator-produced flowsheet is unlikely to follow all the conventions of PFDs given in Chapter 1 regarding equipment symbols, line crosses, labels, and so on. Second, the process simulated is not the true process. One unit in the process simulator (such as a distillation column) maybe several pieces of equipment (tower, condenser, condensate tank, etc.) that need to be shown on a PFD. It is common to simulate a sin e unit (such as a process-process heat exchanger) as two units to decouple the recycle calculations. Some units, such as a storage tank, require no calculations in the process simulator and thus are not shown on its flowsheet. However, the simulator flowsheet is essential in the appendix of the report if the simulator report is included. Care should be taken to use the same stream numbers in the simulation flowsheet as in the PFD whenever possible. 

Y32.11-196KR1998) Graphic Symbols for Process Flow Diagrams in Petrolenm and Chemical Indnstries Order No. K00040 29.00... 

This diagram may appear trivial to the expert chemist but for a novice it contains much information about the chemical reaction at both the sub-micro and symbolic levels presented in multiple representational formats. Unless teachers are explicit in their use of these representations it is umealistic to assume that students would develop the same ability to choose an appropriate representation for a given process. It is possible that students can use and understand the representations without being able to see how they are related. Several authors (Hinton and Nakhleh, 1999 Kozma and Russell, 1997 Nurrenbem and Pickering, 1987) suggest that students are made aware of all three levels of representations and given opportunities to use them in solving problems. 

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